Method for reducing growth of weeds



States Patent Patented Oct. 27, 1959 sodium decyl benzene sulfonate, sodium dipropyl naphthalene sulfon ate or sodium butyl naphthalene sul- METHOD FOR REDUCING GROWTH OF WEEDS The following examples illustrate in detail how the 2 4-dichloro-6-nitrophenol can be employed in accordance Willard B. Jordan, Baldwin Md. asslgnor to Olin Mathiejson Chemical Corporation, a corporation of Virginia W my mvennon and also lllufitrate how the composl' tron can be formulated. As Wlll be apparent to those No Drawing. application August 26, 1954 skilled in the art, other methods of application and 5811111 452,451 formulations are also suitable.

2 Claims. (Cl. 71-23) EXAMPLE I Test plots were prepared in shallow boxes measuring 14 by 28 by 3 /2 inches. These plots were planted with This invention relates to a novel method for the se- 1 Seeds of a single Species of plant Weeds or p le tive ontrol of th growth of plants and passed by means of a moving belt under a spray More particularly, my invention relates to a method which appliedva solution composed of 0.4 pound of in whi h 2,4-di h1om-6-nitr h 1 a d compositions 2,4-d1chloro-6-n1trophenol or other chemical herbicide containing this compound is used as a herbicide for Weeds per gallon of acetone to each plot uniformly. The rate and grasses, at the same time permitting the growth of of application was equivalent to 16 pounds of the divaluable crops. Thus, the method of my invention comchloronitrophenol per acre. After six weeks in the greenprises the application of 2,4-dichloro-6-nitrophenol to house, the plots were examined and the proportion of the soil as a pro-emergence herbicide. This permits the growth recorded. The results of the tests are set forth growth of valuable crops such as corn, Wheat, soya beans in Table I below. In that table 0 indicates that the and cotton, while preventing the growth of weeds, such chemical had .no effect on growth and 10 indicates that as rye grass, crab grass, pigweed and mustard. The rate the chemical completely killed all of the plants in the of application of the 2,4-dichloro-6-nitrophenol will genentire plot. Thus, a value of 9 indicates that 90 pererally vary from about 5 to 25 pounds per acre, about cent of the area of the plot contained no growing plants.

Table I Compound Bye Crab Plg- Mus- Total Corn Cotton Wheat Soy Total Grass Grass weed tsrd B 2,4-Diohloro-6-nitroph enol 9 9 0 10 38 0 O 2 1 3 Diethylene glycol di(2,4-diehlorophenoxyacetate) 4 3 9 9 25 4 5 1 3 13 2Chloroethyl-Z,A-dichlorophenoxyacetate 8 8 9 9 84 8 9 2 9 28 2,4,5 Trichlorophenoxyethoxyethyl 2,4

dichlorophenoxyacctate 9 1 8 6 24 2 7 10 1 20 Sodium trichloroacetate.. 0 0 0 0 0 1 1 l O 3 Alkanolamine salts of dinitr phenol 6 5 8 10 29 0 0 0 0 0 iso-Propyl-N-(3-ch1orophenyl) carbamate. 9 9 9 9 36 2 0 0 2 4,

10 to 20 pounds per acre usually giving very effective It will be noted that three of the chemicals tested were results. 2,4-dich1orophenoxyacetate derivatives and they showed 2,4-dichloro-6-nitrophenol is a yellow solid which melts only a slight selectivity for the weeds as compared with at l22-3 C. and which is further described in Beilstein, the crops. Sodium trichloroacetate was substantially in- 6, 241. When used for the purposes sf my irvention, active as1 ahherbitgidel Theb salts ofhdinigoplhengl anal the compound can be formulated an applie in ac lsopropy c orop eny car amate s owe t e esire cordance with procedures which are well understood in the type of selective herbicidal action in being effecart. For example, the 2-4dich1oro-6-nitrophenol can tive against the weeds but permitting the growth of be admixed with a liquid or, when finely ground, it can the crops. However, the 2,4-dichloro-6-nitrophenol used be admixed with a solid diluent. Suitable concentrates in accordance with my invention is more selective than can be prepared which can be further diluted before apthe two preceding compounds, both of which are complication to the soil. Thus, concentrated solutions in mercially available for this purpose. acetone, cyclohexanone or aromatic petroleum oils such as Sovacide F can be prepared, if desired. Preferably EXAMPLE II such concentrated solutions will also contain suitable I 11 order to prepare a wettable powder suitable for emulslfylfig i s l 20 (a i g use in accordance with my invention when diluted with il i 0 f inono i i; from 200 to 500 parts by weight of water, 4 parts by 5: b (a j i g' Suing a i weight of 2,4-dichloro-6-nitrophenol, 0.5 part by weight 8 concentla e 1 can 3 of finely divided talc (350 mesh) and 0.5 part by weight Water to slispenslois 9 ssons are Sm of Carbowax 4000 (a proprietary non-volatile, solid polya e for t manor to e y i ethylene glycol which is hard and waxy in nature, has

Alternatively, the finely divided dichloronitrophenol o a specific gravity of 1.2, a freezing range of 5035 C.,

can be admixed WIth finely d1v1ded d1luents, for example, 65 a flash paint above 4750 F. and a saybolt viscosity at attapulgite, Cehte, finely cl1v1ded talc, benton1te,pyrophyl- 0 R of 5O0 7O0 seconds) are intimately admixed.

lite, calcium carbonate or the like. When used as a spray in aqueous solution or suspension, such solid admixtures will advantageously contain also a wetting EXAMPLE agent, for example, an alkyl aryl sulfonate such as An aerosol suitable for use 1n accordance with my invention can be prepared by dissolving one part by weight of 2,4-dichloro-6-nitrophenol in a mixture composed of 89 parts by weight of dichlorodifluoromethane and 10 parts by weight of cyclohexanone.

EXAMPLE IV An emulsifiable concentrate suitable for use in accordancewith my invention when diluted with 50 parts by Weight of water per part of concentrate is composed ofanadmixture of one part by weight of 2,4-dichloro-6- nitrophenol and 10 parts by weight of Tween No. 20.

I claim:

1. A method for reducing the growth of Weeds and grasses among growing crops which comprises applying to the soil prior to the emergence of the said weeds, grasses and crops 2,4-dichloro-6-nitrophenol in amount effective to substantially reduce the growth of the weeds 15 and grasses.

2. A method according to claim 1 in which the rate of application of the 2,4-dichloro-6-nitrophenol to the soil is from about 5 to about 25 pounds per acre.

References Cited in the file of this patent UNITED STATES PATENTS 2,344,063 Schotte Mar. 14, 1944 2,410,281 Fletcher Oct. 29, 1946 FOREIGN PATENTS 896,478 France May 2, 1944 OTHER REFERENCES Comptes Rendus des Seances de lAcadmie des Sciences, vol. 216 (1943), pages 79 to 81. 

1. A METHOD FOR REDUCING THE GROWTH OF WEEDS AND GRASSES AMONG GROWING CROPS WHICH COMPRISES APPLYING TO THE SOIL PRIOR TO THE EMERGENCE OF THE SAID WEEDS, GRASSES AND CROPS 2,4-DICHLORO-6-NITROPHENOL IN AMOUNT EFFECTIVE TO SUBSTANTIALLY REDUCE THE GROWTH OF THE WEEDS AND GRASSES. 